Struktur Anatomi dan Uji Histokimia Terpenoid dan Fenol Dua Varietas Sirih Hijau (Piper betle L.)

This study aims to determine the anatomical structure and histochemical test of terpenoid and phenol compounds in two varieties of green betel plants (Piper betle). Making leaves anatomical structure preparations using the fresh method, testing terpenoid compounds with 5% copper acetate, testing phenol with ferric trichloride 10% and some grains of sodium carbonate. The observations of the anatomical structure of green betel leaf varieties 1 and varieties 2 have similarities consisting of the upper epidermis, upper hypodermis, palisade parenchyma, parenchymal sponges, vascular bundles (xylem and phloem), sclerenchyma, cholenchyma, lower epidermis, lower hypodermis, secretory cells, trichoma, stoma and calcium oxalate crystals, and in varieties 2 look more trichomes. The anatomical structure of the variety 1 betel stem and varieties 2 are arranged from the outside in the direction of the epidermal tissue, colenchymal tissue, cortical bundles, sclerenchyma, cortex, medullary and peripheral vascular files, pith, the central part of the stem is a secretory gland. Phenol in betel vine varieties 1 and varieties 2 is positive in the secretion cell part which is spread in the parenchymal tissue of the mother's leaf bone and lamina, whereas in the stem is spread around the cortex and pith parenchyma. Positive secretion cells contain phenol not as much as secretory cells containing terpenoids. Based on quantitative observations the size of oil cell density and secretion cell diameter, the essential oils contained in the cell secretions in the leaves of variety 1 are more than varieties 2 while in the varieties 2, there are more varieties 1.

Transcriptional switch for programmed cell death in pith parenchyma of sorghum stems

Pith parenchyma cells store water in various plant organs. These cells are especially important for producing sugar and ethanol from the sugar juice of grass stems. In many plants, the death of pith parenchyma cells reduces their stem water content. Previous studies proposed that a hypothetical D gene might be responsible for the death of stem pith parenchyma cells in Sorghum bicolor, a promising energy grass, although its identity and molecular function are unknown. Here, we identify the D gene and note that it is located on chromosome 6 in agreement with previous predictions. Sorghum varieties with a functional D allele had stems enriched with dry, dead pith parenchyma cells, whereas those with each of six independent nonfunctional D alleles had stems enriched with juicy, living pith parenchyma cells. D expression was spatiotemporally coupled with the appearance of dead, air-filled pith parenchyma cells in sorghum stems. Among D homologs that are present in flowering plants, Arabidopsis ANAC074 also is required for the death of stem pith parenchyma cells. D and ANAC074 encode previously uncharacterized NAC transcription factors and are sufficient to ectopically induce programmed death of Arabidopsis culture cells via the activation of autolytic enzymes. Taken together, these results indicate that D and its Arabidopsis ortholog, ANAC074, are master transcriptional switches that induce programmed death of stem pith parenchyma cells. Thus, targeting the D gene will provide an approach to breeding crops for sugar and ethanol production.

Anatomical and morphological features of seedlings of some Cactoideae Eaton (Cactaceae Juss.) species

<p>Three-month-old seedlings of 11 species of the subfamily Cactoideae (<em>Melocactus bahiensis</em>, <em>Melocactus curvispinus</em>, <em>Echinopsis eyriesii</em>, <em>E. mirablis</em>, <em>E. peruviana</em>, <em>Oreocereus celsianus</em>, <em>Rebutia flavistyla</em>, <em>Rebutia minuscula</em>, <em>Astrophytum myriostigma</em>, <em>Mamillaria columbiana</em>, and <em>M. prolifera</em>) have been studied. These plants exhibit a uniseriate epidermis, covered by a thin cuticle. Except for <em>E. peruviana</em> and <em>A. myriostigma</em>, no hypodermis could be detected. The shoots of all studied specimens consist mainly of cortex parenchyma with large thin-walled cells. The pith parenchyma is composed of much smaller cells. Due to the fact that the cortex parenchyma comprises the largest portion of the cross-sectional area, it can be concluded that it is the main water-storing tissue. The extent of vascular tissue development varies. Collateral vascular bundles are present in the stele. The studied seedlings contain various ergastic substances, in particular inclusions of calcium oxalate (all studied species), starch (<em>Mammillaria prolifera</em>, <em>E. mirabilis</em>, and the genus <em>Melocactus</em>), inulin-like inclusions, and occasionally lipid drops (some <em>Echinopsis</em> species).</p><p>Thus, it was found that all studied plants have a highly specialized anatomical and morphological structure. At the same time, the epidermis and hypodermis are poorly developed. Accordingly, the adaptation to arid conditions of the examined seedlings involves an increased growth of the water-storing tissue and the production of ergastic substances.</p>

Morphogenesis of stem gall tissues induced by larvae of two cecidomyiid species (Diptera: Cecidomyiidae) on Suaeda monoica (Chenopodiaceae)

Izeniola obesula Dorchin and Stefaniola defoliata Dorchin (Diptera: Cecidomyiidae: Lasiopterini) are monophagous gall midges each inducing a unique kind of gall on stems of the salt marsh plant Suaeda monoica Gmelin (Chenopodiaceae). The morphogenesis of these two types of galls was studied in relation to the life history of the midges as observed both in the field and the laboratory. Izeniola obesula larvae penetrate the pith parenchyma through the growing shoot apex, causing intensive cell proliferation and inducing differentiation of novel vascular tissues and a sclerenchyma sheath around their chambers. Vascular differentiation in this gall originates from the larval chamber, a phenomenon attributed to local stimulation by the larva. It is suggested that the sclerenchyma layer in these galls is also induced by insect activity. Stefaniola defoliata larvae penetrate the stem laterally and reside inside the primary phloem, causing proliferation of phloem parenchyma, and are later encapsulated by secondary xylem tissue. Both galls are associated with a symbiotic fungus that grows along the inner walls of the larval chambers. The possible hormonal mechanisms controlling morphogenesis of the galls are discussed.Key words: gall morphogenesis, phytohormones, sclerenchyma, vascular differentiation.

Morphological and histochemical analysis of galls of Lipara lucens (Diptera, Chloropidae) on Phragmites australis (Poaceae)

Lipara lucens Meigen (Diptera, Chloropidae) is a monophagous herbivore of the common reed, Phragmites australis Cav. (Trin.) ex Steud. (Poaceae), on which it induces typical cigar-shaped galls. In this paper, the anatomy and histochemistry of galls, cultivated in a greenhouse and collected in the field, were examined. Gall growth takes place while the larva feeds outside the actual developing gall. During gall growth, internode elongation is reduced. Internally, the pith parenchyma, destined to become the nutritive tissue, proliferates instead of degenerating as is seen in uninfested stems. The tissue cylinder around the gall chamber widens up to three times its normal size, while the pith parenchyma doubles its width. The central pith of nutritive cells becomes surrounded by an inner layer of longitudinal and an outer layer of radial parenchymatous cells. Vascular strands, likely connected to the vascular tissue of the host plant, run through this special band of parenchyma cells. The bundles are oriented perpendicular to the stem axis, surrounding the larval chamber. When the gall is completed, the larva gnaws through the growing point and enters the gall chamber, where it consumes the nutritive tissue. A sclerenchymatization process starts now resulting in an extremely hardened gall. Histochemical staining reveals the presence of proteins, DNA, RNA, and a gradient of lipid globules in the nutritive tissue. No starch was detected.Key words: plant-insect interactions, Lipara lucens, Phragmites australis, gall structure.

Comparative anatomy of colonization of cotton hypocotyls and roots by virulent and hypovirulent isolates of Rhizoctonia solani

The hypovirulent (HV) isolate (No. 521) densely colonized the outer surface of the hypocotyls and roots of radish and cotton seedlings but did not penetrate into the cortical parenchyma, whereas the virulent (V) isolate (No. 82) penetrated the root and hypocotyl tissues (except for the xylem vessels) to the center of the pith parenchyma. The HV isolate did not cause any degradation of the cell wall material except for the cuticular layer that had disappeared in the regions of close contact between the hyphae and the epidermal outer surface. During the prepenetration stages of the V isolate, the cell walls of the seedlings underwent a significant, visible degradation. The cuticle between the hyphae and the epidermis was detached and degraded. The HV isolate seems to densely cover the outer surface of the seedlings, and it may occupy the possible infection sites, rendering recognition and occupation of such sites unavailable for the virulent pathogen.